The present invention relates to a programmable synthetic-speech calculator or micro computer capable of releasing synthesized sound only when the calculator or micro computer operates in a program mode.
It is known in the art of electronic calculators that synthesized sound signals may be released in response to depression of a specific key in a general calculation mode (or a normal mode). Calculations executed in the normal mode are almost always momentary and information keyed can be visually checked while an operator watches a visual display provided on a display panel. Generating sound signals indicative of information keyed is harsh to the operator's eye. To prevent this there can be provided a switch for selecting a sound bearing mode or a non sound bearing or silient mode. However, this switch is somewhat complicated in terms of operation.
For programmable calculators it is not permitted to erroneously load an incorrect program into calculators by depressions of incorrect keys. Once a specific program has been entered calculations will be performed in accordance with such a program. In addition, it is bothersome to check the contents of the loaded program whenever desired. Program information keyed can not be easily confirmed during entry of that program information in a prior art programmable calculator although being visually displayed in the form of symbols or characters.
It is also obvious to provide multi-function keys such as cos/2 along with a distinction key F available to establish a distinction between the functions assigned by the multi-functions. For example, when keys F and cos/2 are sequentially operated in order to designate "cos", a program memory is not necessarily loaded with key codes indicative of the key F and, then upon further depression of the key cos/2 , is permitted to store key codes indicative of the designated function "cos" through a synthesis process. In this case a visual display of program instructions remains unchanged even upon depression of the key F and the instruction "cos" is thereafter displayed upon depression of the key cos/2 . Therefore, whether the key F has been actuated can not be visually determined nor confirmed.
An END instruction for completing a specific program and a HALT instruction to enable the user to enter new information during the execution of calculations are useful instructions in programmable calculators. Since program or complicated calculations need a substantially long period of time to complete (for example, ranging from more than one minute to more than one hour), whether there is the END code can only be determined by watching the display panel throughout the long period of time. Similarly, it is not predictable when the halt condition is reached.
Accordingly, it is an object of the present invention to provide a programmable synthetic-speech calculator or micro computer provided with a means for releasing synthetic sounds in response to actuation of keys on a keyboard means only when operating in a program mode.
Synthetic sounds indicative of an END instruction, a HALT instruction, a PAUSE instruction, a JUMP instruction and other particular program instructions man also be generated in accordance with the present invention.